[C-libcurl] Support setting basePath and apiKeys when creating an apiClient

Created by: ityuhui

After generating a C client, user will use apiClient_create to create an apiClient to execute REST request operation.

But for now, apiClient_create does not accept any parameter so apiClient cannot get any user setting. e.g.

apiClient_t *apiClient_create() {
    curl_global_init(CURL_GLOBAL_ALL);
    apiClient_t *apiClient = malloc(sizeof(apiClient_t));
    apiClient->basePath = "http://localhost";
    apiClient->dataReceived = NULL;
    apiClient->response_code = 0;
    apiClient->apiKeys = NULL;

    return apiClient;
}

I added a new function "apiClient_create_with_base_path" to get user settings:

apiClient_t *apiClient_create_with_base_path(const char *basePath
, list_t *apiKeys
) {
    curl_global_init(CURL_GLOBAL_ALL);
    apiClient_t *apiClient = malloc(sizeof(apiClient_t));
    if(basePath){
        apiClient->basePath = strdup(basePath);
    }else{
        apiClient->basePath = strdup("http://localhost");
    }
    apiClient->dataReceived = NULL;
    apiClient->response_code = 0;
    if(apiKeys!= NULL) {
        apiClient->apiKeys = list_create();
        listEntry_t *listEntry = NULL;
        list_ForEach(listEntry, apiKeys) {
            keyValuePair_t *pair = listEntry->data;
            keyValuePair_t *pairDup = keyValuePair_create(strdup(pair->key), strdup(pair->value));
            list_addElement(apiClient->apiKeys, pairDup);
        }
    }else{
        apiClient->apiKeys = NULL;
    }

    return apiClient;
}

And I also updated the header file and apiClient_free.

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